A Senate panel took the Food and Drug Administration to task yesterday for its "inexcusable" response to pet food contamination and a month's worth of expanding recalls that have left Americans fearful about what to feed their cats and dogs.

The Appropriations subcommittee, with a special appearance by the dean of the Senate, pressed the agency for better and faster reporting about tainted food and better and more-frequent inspections of pet food factories.

"This is inexcusable," Sen. Richard J. Durbin (D-Ill.) said after a two-hour hearing in which an FDA official said he couldn't be sure that all the adulterated pet food has been recalled and is off store shelves. "The FDA's response to this situation has been wholly inadequate."

An industry representative noted that only 1 percent of the pet food on the market has been recalled as tainted, but Sen. Robert F. Bennett (R-Utah) said that's no comfort to those whose pets have been affected. "I'd like to know how lethal that 1 percent really is," he said.

Seven weeks after Menu Foods discovered a problem and a month after making it public, no one knows how many animals have died. The FDA, which began a wide-ranging investigation immediately after learning of the recall, determined that the likely source of the toxin was an ingredient from China and banned all imports of wheat gluten from that country.

Durbin, who requested the hearing and who plans to introduce legislation tightening regulations, said the contamination and the government's response expose a significant risk to human as well as pet food supplies. He proposed creating one food safety administration with the budget and staff to coordinate all food inspections. Pet food manufacturers "ought to be on notice to notify the FDA when there's a suspicion of a problem, or face penalties," he said.

Sen. Herb Kohl (D-Wis.), the subcommittee's chairman, called the FDA's Web site bewildering, pointing out that people in search of recall information were directed to manufacturers' Web sites. The agency's representative agreed that it needs improvement.

The unexpected appearance of the Appropriations Committee Chairman, Sen. Robert C. Byrd (D-W.Va.), drove home the message that the issue is one that matters deeply to millions.

In rambling but heartfelt statements and queries, Byrd discussed his Shih Tzu, whom his late wife named Trouble, he said, and whom he calls Baby. The dog often spends his day at the Senate.

"As a pet owner and dog-lover, I join with many millions of Americans in anxiously hoping I didn't poison my dog with a special snack or serving of food," said the Senate's most senior member.

Earlier in the day, the FDA warned consumers that some of the more than 100 brands of pet food that contain adulterated wheat gluten may still be in stores. The FDA made about 400 spot-checks and found that some banned products still had not been removed.

Elizabeth Hodgkins, a veterinarian from Yorba Linda, Calif., told the subcommittee that pet food labels should not be able to make safety claims without rigorous ingredient testing by the maker or the supplier. Pet food labels carry only nutritional guarantees, said Eric Nelson, president of the American Association of Feed Control Officers.

Menu Foods officials declined to attend the hearing and were represented by the Pet Food Institute, a trade association. The institute's president, Duane Ekedahl, said the industry is forming a private-public commission to investigate how the pet food became tainted and to recommend steps to improve safety.

He called pet food "perhaps the most highly regulated product on store shelves" and asserted that "pet food is safe" and that regulation should be left to the marketplace.

Durbin pounced.

"Do you think Menu Foods met the standard of care that the pet food manufacturing should live up to?" Durbin asked. Ekedahl said he had no direct knowledge of the matter.

"Menu Foods waited more than three weeks after the dogs wouldn't eat their food to notify the FDA," Durbin persisted.